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BACKGROUND: Cutaneous leishmaniasis (CL) caused by Leishmania (Viannia) braziliensis is associated with an inflammatory response. Granzyme (GzmB) and IL-1ß play a key role in the pathology. Meglumine antimoniate (MA) is the first-choice drug for the treatment of CL, but therapy failure is observed in up to 50% of the cases. The protein, rSm29 of Schistosoma mansoni, down-modulates pro-inflammatory cytokine production. We evaluate if the combination of topical rSm29 plus MA increases the cure rate of CL. METHODS: In this randomized clinical trial, 91 CL patients were allocated in 3 groups. All cases received MA (20 mg/kg/weight) for 20 days. Group 1 used topical rSm29 (10 µg), group 2 a placebo topically applied, and group 3 received only MA. RESULTS: The cure rate on day 90 was 71% in subjects treated with rSm29 plus MA, and 43% in patients who received MA plus placebo or MA alone (P < 0.05). There was a decrease in GzmB and an increase in IFN-γ (P < 0.05) in supernatants of skin biopsies of the lesions obtained on D7 of therapy (P < 0.05) in patients who received rSm29. CONCLUSION: rSm29 associated with MA reduces GzmB levels, is more effective than MA alone, and decreases CL healing time. CLINICAL TRIALS REGISTRATION: ClinicalTrial.gov under NCT06000514.
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Administração Tópica , Antiprotozoários , Quimioterapia Combinada , Leishmaniose Cutânea , Antimoniato de Meglumina , Compostos Organometálicos , Humanos , Leishmaniose Cutânea/tratamento farmacológico , Leishmaniose Cutânea/parasitologia , Antimoniato de Meglumina/uso terapêutico , Antimoniato de Meglumina/administração & dosagem , Masculino , Feminino , Adulto , Antiprotozoários/uso terapêutico , Antiprotozoários/administração & dosagem , Pessoa de Meia-Idade , Adulto Jovem , Compostos Organometálicos/uso terapêutico , Compostos Organometálicos/administração & dosagem , Resultado do Tratamento , Meglumina/administração & dosagem , Meglumina/uso terapêutico , Adolescente , Animais , Leishmania braziliensis/efeitos dos fármacos , Administração Intravenosa , Granzimas/metabolismoRESUMO
BACKGROUND: The mechanisms that mediate immune protection in individuals with subclinical (SC) or asymptomatic infection with L. braziliensis are largely unknown. Neutrophils (PMNs) have been implicated in progressive symptomatic cutaneous leishmaniasis (CL), but their potential participation in maintenance of subclinical infection is unexplored. The aim of this study was to compare the phenotypic and functional profiles of PMNs in individuals with SC infection versus patients with symptomatic CL due to L. braziliensis. METHODS: Subjects were recruited in the endemic region of Corte de Pedra, Bahia, Brazil. Surface markers to define activation status were characterized by flow cytometry. Functional responses of PMNs including phagocytic capacity, production of oxidative species, and oxidative killing of intracellular parasites were studied in vitro. RESULTS: PMNs from individuals with SC infection displayed a more activated phenotype and greater ability to control the infection than PMNs from patients with CL. In contrast, PMNs from patients with CL exhibited higher expression of HLA-DR and higher production of oxidative species than PMNs from subjects with SC infection. CONCLUSION: PMNs from individuals with SC infection can control the infection more efficiently than PMNs from patients with CL, despite the lower production of oxidants. Our observations suggest that L. braziliensis may evade microbicidal mechanisms of PMNs from patients with CL, contributing to parasite dissemination and the establishment of disease.
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Leishmaniasis, caused by Leishmania parasites, is a neglected tropical disease and Cutaneous Leishmaniasis (CL) is the most common form. Despite the associated toxicity and adverse effects, Meglumine antimoniate (MA) remains the first-choice treatment for CL in Brazil, pressing the need for the development of better alternatives. Bacterial NanoCellulose (BNC), a biocompatible nanomaterial, has unique properties regarding wound healing. In a previous study, we showed that use of topical BNC + systemic MA significantly increased the cure rate of CL patients, compared to treatment with MA alone. Herein, we performed a study comparing the combination of a wound dressing (BNC or placebo) plus systemic MA versus systemic MA alone, in CL caused by Leishmania braziliensis. We show that patients treated with the combination treatment (BNC or placebo) + MA showed improved cure rates and decreased need for rescue treatment, although differences compared to controls (systemic MA alone) were not significant. However, the overall time-to-cure was significantly lower in groups treated with the combination treatment (BNC+ systemic MA or placebo + systemic MA) in comparison to controls (MA alone), indicating that the use of a wound dressing improves CL treatment outcome. Assessment of the immune response in peripheral blood showed an overall downmodulation in the inflammatory landscape and a significant decrease in the production of IL-1a (p < 0.05) in patients treated with topical BNC + systemic MA. Our results show that the application of wound dressings to CL lesions can improve chemotherapy outcome in CL caused by L. braziliensis.
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The role of the immune response in the pathogenesis of cutaneous leishmaniasis (CL) due to Leishmania (Viannia) braziliensis is predominantly carried out via blood cells. Here, we evaluate whether cytokine production by peripheral blood mononuclear cells (PBMCs) reflects what has been documented at the lesion site. The participants included 22 CL patients diagnosed with a positive PCR. PBMCs were stimulated for 72 h with a soluble leishmania antigen (SLA). Biopsies obtained from the edge of the ulcers were incubated for the same period. Cytokines in supernatants were assessed via ELISA. TNF, IL-1ß, IL-6, IL-17, and granzyme B (GzmB) were higher in the supernatants of biopsies than in PBMCs, but IFN-γ was higher in the supernatants of PBMCs than in biopsies. There was a positive correlation between IFN-γ and TNF in PBMCs, and an inverse correlation between TNF and IL-10 in the cells from the lesion site. A strong correlation between IL-1ß, IL-17, and GzmB was observed in the biopsies, and a positive correlation was detected between these cytokines and the lesion size. Our results indicate that the immune response in L. braziliensis lesions is different from that observed in peripheral blood, and our data suggest that in addition to IL-1ß and GzmB, IL-17 participates in the pathology of CL.
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Cutaneous leishmaniasis (CL) caused by Leishmania braziliensis, is a disease characterized by well-limited ulcerated lesions with raised borders in exposed parts of the body. miRNAs are recognized for their role in the complex and plastic interaction between host and pathogens, either as part of the host's strategy to neutralize infection or as a molecular mechanism employed by the pathogen to modulate host inflammatory pathways to remain undetected. The mir155 targets a broad range of inflammatory mediators, following toll-like receptors (TLRs) signaling. In this work, we evaluated the effects of the expression of miR155a-5p in human macrophages infected with L. braziliensis. Our results show that miR155a-5p is inversely correlated with early apoptosis and conversely, seems to influence an increment in the oxidative burst in these cells. Altogether, we spotted a functional role of the miR155a-5p in CL pathogenesis, raising the hypothesis that an increased miR-155 expression by TLR ligands influences cellular mechanisms settled to promote both killing and control of parasite density after infection.
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Leishmania braziliensis , Leishmaniose Cutânea , MicroRNAs , Humanos , Leishmania braziliensis/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Macrófagos/metabolismo , Leishmaniose Cutânea/parasitologia , MicroRNAs/genética , Apoptose/genéticaRESUMO
Disseminated leishmaniasis (DL) is an emergent severe disease manifesting with multiple lesions. To determine the relationship between immune response and clinical and therapeutic outcomes, we studied 101 DL and 101 cutaneous leishmaniasis (CL) cases and determined cytokines and chemokines in supernatants of mononuclear cells stimulated with leishmania antigen. Patients were treated with meglumine antimoniate (20 mg/kg) for 20 days (CL) or 30 days (DL); 19 DL patients were instead treated with amphotericin B, miltefosine, or miltefosine and meglumine antimoniate. High levels of chemokine ligand 9 were associated with more severe DL. The cure rate for meglumine antimoniate was low for both DL (44%) and CL (60%), but healing time was longer in DL (p = 0.003). The lowest cure rate (22%) was found in DL patients with >100 lesions. However, meglumine antimoniate/miltefosine treatment cured all DL patients who received it; therefore, that combination should be considered as first choice therapy.
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Leishmania braziliensis , Leishmania , Leishmaniose Cutânea , Fosforilcolina/análogos & derivados , Humanos , Antimoniato de Meglumina/uso terapêutico , Leishmaniose Cutânea/diagnóstico , Leishmaniose Cutânea/tratamento farmacológicoRESUMO
Background: Leishmaniasis is an infectious disease caused by protozoa of the genus Leishmania. There are still no vaccines, and therapeutic options are limited, indicating the constant need to understand the fine mechanisms of its pathophysiology. An approach that has been explored in leishmaniasis is the participation of microRNAs (miRNAs), a class of small non-coding RNAs that act, in most cases, to repress gene expression. miRNAs play a role in the complex and plastic interaction between the host and pathogens, either as part of the host's immune response to neutralize infection or as a molecular strategy employed by the pathogen to modulate host pathways to its own benefit. Methods: Monocyte-derived macrophages from healthy subjects were infected with isolates of three clinical forms of L. braziliensis: cutaneous (CL), mucosal (ML), and disseminated (DL) leishmaniasis. We compared the expression of miRNAs that take part in the TLR/NFkB pathways. Correlations with parasite load as well as immune parameters were analyzed. Results: miRNAs -103a-3p, -21-3p, 125a-3p -155-5p, -146a-5p, -132- 5p, and -147a were differentially expressed in the metastatic ML and DL forms, and there was a direct correlation between miRNAs -103a-3p, -21-3p, -155-5p, -146a-5p, -132-5p, and -9-3p and parasite load with ML and DL isolates. We also found a correlation between the expression of miR-21-3p and miR-146a-5p with the antiapoptotic gene BCL2 and the increase of viable cells, whereas miR-147a was indirectly correlated with CXCL-9 levels. Conclusion: The expression of miRNAs is strongly correlated with the parasite load and the inflammatory response, suggesting the participation of these molecules in the pathogenesis of the different clinical forms of L. braziliensis.
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Leishmania , Leishmaniose Cutânea , MicroRNAs , Humanos , Estados Unidos , MicroRNAs/genética , MicroRNAs/metabolismo , Macrófagos/metabolismo , PeleRESUMO
Exosomes, organelles measuring 30-200nm, are secreted by various cell types. Leishmania exosomes consist of many proteins, including heat shock proteins, annexins, Glycoprotein 63, proteins exerting signaling activity and those containing mRNA and miRNA. Studies have demonstrated that Leishmania donovani exosomes downregulate IFN-γ and inhibit the expression of microbicidal molecules, such as TNF and nitric oxide, thus creating a microenvironment favoring parasite proliferation. Despite lacking immunological memory, data in the literature suggest that, following initial stimulation, mononuclear phagocytes may become "trained" to respond more effectively to subsequent stimuli. Here we characterized the effects of macrophage sensitization using L. braziliensis exosomes prior to infection by the same pathogen. Human macrophages were stimulated with L. braziliensis exosomes and then infected with L. braziliensis. Higher levels of IL-1ß and IL-6 were detected in cultures sensitized prior to infection compared to unstimulated infected cells. Moreover, stimulation with L. braziliensis exosomes induced macrophage production of IL-1ß, IL-6, IL-10 and TNF. Inhibition of exosome secretion by L. braziliensis prior to macrophage infection reduced cytokine production and produced lower infection rates than untreated infected cells. Exosome stimulation also induced the consumption/regulation of NLRP3 inflammasome components in macrophages, while the blockade of NLRP3 resulted in lower levels of IL-6 and IL-1ß. Our results suggest that L. braziliensis exosomes stimulate macrophages, leading to an exacerbated inflammatory state that may be NLRP3-dependent.
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Exossomos , Leishmania braziliensis , Leishmania donovani , Humanos , Proteína 3 que Contém Domínio de Pirina da Família NLR , Interleucina-6/farmacologia , MacrófagosRESUMO
Patients with cutaneous leishmaniasis (CL) present an exacerbated inflammatory response associated with tissue damage and ulcer development. In recent years, higher rates of failure to pentavalent antimoniate therapy have been observed, yet the underlying reason remains poorly understood. We hypothesize that the eicosanoid PGE2 favours the establishment of infection by L. braziliensis, which contributes to therapeutic failure. The aim of the present study was to investigate the influence of PGE2 on the survival of L. braziliensis in macrophages and rates of therapeutic failure in CL patients. PGE2, an eicosanoid derived from the metabolism of arachidonic acid by the COX-2 enzyme, plays several roles in immune response. We found that increased PGE2 decreases the microbicidal function of macrophages and is associated with disease severity and therapeutic failure. Additionally, the neutralization of COX-2 by NS398, a selective NSAID, increases the ability of macrophages to kill L. braziliensis and protects against the pathological inflammatory response. Our data suggest that NS398 may serve as an adjunct treatment for CL patients.
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Leishmania braziliensis , Leishmaniose Cutânea , Humanos , Dinoprostona , Ciclo-Oxigenase 2/genética , Ciclo-Oxigenase 2/uso terapêutico , Leishmaniose Cutânea/tratamento farmacológicoRESUMO
This case-control study compared the clinical profile, parasite load, polymerase chain reaction positivity, and response to therapy in patients with recurrent cutaneous leishmaniasis (RCL) with primary cutaneous leishmaniasis (CL). The RCL patients had milder diseases with lower parasite loads, a lower number of lesions, and more self-healing diseases than primary CL patients.
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Dogs play an important role in transmission of Leishmania infantum, but epidemiologic and clinical studies of canine tegumentary leishmaniasis (CTL) are scarce. In an endemic area of human American tegumentary leishmaniasis (ATL) caused by Leishmania braziliensis, we determine the prevalence and incidence of both CTL and subclinical (SC) L. braziliensis infection in dogs and evaluated if the presence of dogs with CTL or SC L. braziliensis infection is associated with the occurrence of human ATL. SC infection in healthy animals and CTL in animals with ulcers were determined by PCR on biopsied healthy skin or on ulcers or by detecting antibodies against soluble leishmania antigen. We compared the occurrence of human ATL in homes with dogs with CTL or SC infection with control homes without dogs or with dogs without CTL or SC infection. The prevalence of SC infection was 35% and of CTL 31%. The incidence of SC infection in dogs was 4.6% and of CTL 9.3%. The frequency of ATL in humans was 50% in homes with infected dogs and 13% in homes without L. braziliensis infection in dogs. CTL and SC infection is highly prevalent, and dogs may participate in the transmission chain of L. braziliensis.
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In Brazil, Leishmania braziliensis is the main causative agent of the neglected tropical disease, cutaneous leishmaniasis (CL). CL presents on a spectrum of disease severity with a high rate of treatment failure. Yet the parasite factors that contribute to disease presentation and treatment outcome are not well understood, in part because successfully isolating and culturing parasites from patient lesions remains a major technical challenge. Here we describe the development of selective whole genome amplification (SWGA) for Leishmania and show that this method enables culture-independent analysis of parasite genomes obtained directly from primary patient skin samples, allowing us to circumvent artifacts associated with adaptation to culture. We show that SWGA can be applied to multiple Leishmania species residing in different host species, suggesting that this method is broadly useful in both experimental infection models and clinical studies. SWGA carried out directly on skin biopsies collected from patients in Corte de Pedra, Bahia, Brazil, showed extensive genomic diversity. Finally, as a proof-of-concept, we demonstrated that SWGA data can be integrated with published whole genome data from cultured parasite isolates to identify variants unique to specific geographic regions in Brazil where treatment failure rates are known to be high. SWGA provides a relatively simple method to generate Leishmania genomes directly from patient samples, unlocking the potential to link parasite genetics with host clinical phenotypes.
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Genoma de Protozoário , Leishmaniose Cutânea , Parasitologia , Pele , Genoma de Protozoário/genética , Humanos , Genética Populacional , Pele/parasitologia , Brasil , Leishmaniose Cutânea/parasitologia , Parasitologia/métodos , Leishmania braziliensis/genéticaRESUMO
Dogs living in areas of Leishmania (Viannia) braziliensis transmission may present canine tegumentary leishmaniasis (CTL) characterized by cutaneous or muzzle ulcers as well as asymptomatic L. braziliensis infection. It is not clear if dogs participate in the transmission chain of L. braziliensis to humans. However, dogs may remain with chronic ulcers for a long time, and as there are no public policies about CTL, these animals die or are sacrificed. Here we compare the efficacy of intralesional meglumine antimoniate with intralesional 0.9% NaCl solution in CTL treatment. This randomized control study included 32 dogs with cutaneous or muzzle lesions who had L. braziliensis DNA detected by PCR in tissue biopsied. Group one received 5ml of intralesional Glucantime, and group two received 5ml 0.9% NaCl solution, both applied in the four cardinal points on days 0, 15, and 30. Cure was defined as complete healing of the ulcers in the absence of raised borders on day 90. There was no difference in animals' demographic and clinical features in the two groups (p >.05). While at the endpoint, the cure rate was 87.5% in the group test, and in those who received 0.9 NaCl the cure rate was only 12.5%. As important as the high cure rate, the healing time was faster in dogs treated with antimony than in those treated with saline (p < .001). Intralesional meglumine antimoniate is effective in the treatment of dogs with L. braziliensis infection and accelerates the healing time of CTL.
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Antiprotozoários , Leishmania braziliensis , Leishmaniose Cutânea , Compostos Organometálicos , Humanos , Cães , Animais , Antimoniato de Meglumina/uso terapêutico , Antiprotozoários/uso terapêutico , Meglumina/uso terapêutico , Leishmaniose Cutânea/patologia , Solução Salina/uso terapêutico , Úlcera/tratamento farmacológico , Compostos Organometálicos/uso terapêuticoRESUMO
BACKGROUND: Virtually all patients with human T-lymphotropic virus 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) have some degree of erectile dysfunction (ED), but ED is also found in a large percentage of HTLV-1 carriers. AIM: To evaluate the evolution of ED in individuals infected with HTLV-1 who were followed for up to 15 years. METHODS: This prospective cohort study included men infected with HTLV-1 who had ED, were aged 18 to 70 years, and were followed from January 2004 to December 2019. We used the International Index of Erectile Function-5 (IIEF-5), the Expanded Disability Status Scale and Osame Motor Disability Scale, and the Overactive Bladder Symptom Score (OABSS) to define and stratify ED, neurologic disability, and bladder dysfunction, respectively. OUTCOMES: Time to development of severe ED was the main outcome. RESULTS: We studied 90 men with ED (mean ± SD age, 52.8 ± 9.78 years). At baseline, 42 were carriers, 16 had probable HAM/TSP, and 32 had definite HAM/TSP. IIEF-5 was highest among carriers and lowest in patients with definite HAM/TSP, whereas OABSS was lowest in carriers and highest in patients with definite HAM/TSP. Median (IQR) follow-up was 8.50 years (3.00-12.00). IIEF-5 fell significantly from baseline to last follow-up among carriers and patients with probable and definite HAM/TSP. There was an inverse correlation between the IIEF-5 and the OABSS at last follow-up (r = -0.62, P < .001). In survival analysis, the time to development of severe ED was significantly shorter in patients with definite HAM/TSP when compared with carriers (P = .001) and those with probable HAM/TSP (P = .014). The presence of definite HAM/TSP at baseline was independently associated with the development of severe ED, after adjustment for baseline age and proviral load (hazard ratio, 6.74; P = .008). CLINICAL IMPLICATIONS: Formal assessment of erectile function should be part of the routine clinical assessment of individuals infected with HTLV-1; worsening erectile function should alert clinicians to the possibility of neurologic deterioration. STRENGTHS AND LIMITATIONS: This is the first prospective cohort study to describe the course of ED in men infected with HTLV-1. The small sample size and absence of seronegative controls are limitations. CONCLUSION: ED is a slowly progressive clinical manifestation of HTLV-1 infection, and the degree of neurologic compromise at baseline is the main predictor of time to progression to severe ED.
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Pessoas com Deficiência , Disfunção Erétil , Vírus Linfotrópico T Tipo 1 Humano , Transtornos Motores , Paraparesia Espástica Tropical , Masculino , Humanos , Adulto , Pessoa de Meia-Idade , Disfunção Erétil/complicações , Estudos ProspectivosRESUMO
Mucosal leishmaniasis (ML) is a severe form of tegumentary leishmaniasis associated with a persistent inflammatory response. High levels of TNF, IFN-γ, CXCL9 and CXCL10 are found in ML patients, and the association of pentoxifylline with antimony is more effective in decreasing the healing time in ML patients when compared to antimony alone. The present study aimed to investigate the existence of a correlation between cytokine and chemokine production and ML severity and evaluate the potential value of cytokine and chemokine production as marker of therapeutic response in ML patients. This prospective study included 86 subjects in an area of endemic Leishmania braziliensis transmission. Patients diagnosed with ML were classified into clinical stages ranging from I to V according to disease severity. TNF, IFN-γ, CXCL9 and CXCL10 levels were quantified in the supernatant of the mononuclear cell cultures by ELISA before and after treatment with antimony alone or antimony plus pentoxifylline. The median TNF level in the group with mild disease (Stages I-II) was 1064 pg/mL (142-3738 pg/mL), while, in the group with moderate or severe disease (Stages III-V), it was 1941 pg/mL (529-5294 pg/mL) (p = 0.008). A direct correlation was observed between ML clinical severity and levels of TNF production (r = 0.44, p = 0.007). Patients who were treated with antimony and pentoxifylline healed significantly faster than those treated with antimony alone (52 vs. 77 days, hazard ratio = 0.60; 95% confidence interval = 0.38-0.95, p = 0.013). Therapeutic failure was higher in the group that received antimony alone (25% vs. 7%; p = 0.041). There was a significant decrease in CXCL9 after therapy of ML in both groups (p = 0.013; p = 0.043). TNF levels are associated with the severity of mucosal diseases, and pentoxifylline associated with antimony should be the recommended therapy for ML in countries where liposomal amphotericin B is not available.
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HTLV-1-infected individuals may develop a neurologic inflammatory condition known as HTLV-1-associated myelopathy (HAM/TSP), in which the high production of TNF is observed. These patients exhibit higher proviral loads, enhanced production of proinflammatory cytokines and lymphocyte proliferation in comparison to asymptomatic HTLV-1 carriers and those presenting overactive bladder (OAB-HTLV-infected). Metalloproteinases (MMPs) are known to degrade the components of the blood-brain barrier, favoring the migration of infected cells into the central nervous system. Moreover, the unbalanced production of MMPs and their inhibitors (TIMPs) has also been associated with tissue damage. The present work studied the production of MMP-9 and TIMPs in HTLV-1-infected individuals with and without neurological manifestations. HAM/TSP patients presented higher concentrations of MMP-9 in peripheral blood mononuclear cell (PBMC) culture supernatants, as well as a higher MMP-9/TIMP-3 ratio when compared to the other groups studied. MMP-9 levels positively correlated with proviral load and TNF in OAB-HTLV-infected individuals, and the in vitro neutralization of TNF significantly decreased MMP-9 levels in PBMC culture supernatants. Our findings indicate an association between MMP-9 production and the proinflammatory state associated with HTLV-1 infection, as well as HAM/TSP.
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Vírus Linfotrópico T Tipo 1 Humano , Paraparesia Espástica Tropical , Humanos , Leucócitos Mononucleares , Metaloproteinase 9 da Matriz , Provírus , Carga ViralRESUMO
American tegumentary leishmaniasis (TL) caused by Leishmania braziliensis is characterized by a spectrum of clinical presentations, ranging from localized cutaneous ulcers (CL), mucosal (ML), or disseminated (DL) disease, to a subclinical (SC) asymptomatic form. Current diagnosis based on parasite culture and/or microscopy lacks sensitivity and specificity. Previous studies showed that patients with CL and ML have very high levels of Leishmania-specific anti-α-Gal antibodies. However, the native parasite α-Gal glycotope(s) is(are) still elusive, thus they have not yet been explored for a more accurate TL diagnosis. Using a chemiluminescent immunoassay, we evaluated the seroreactivity of TL patients across its clinical spectrum, and of endemic (EC) and nonendemic healthy controls (NEC) against three synthetic neoglycoproteins (NGP29b, NGP30b, and NGP28b), respectively comprising the L. major-derived type-2 glycoinositolphospholipid (GIPL)-1 (Galfß1,3Manα), GIPL-2 (Galα1,3Galfß1,3Manα), and GIPL-3 (Galα1,6Galα1,3Galfß) glycotopes. Contrary to NGP29b and NGP30b, NGP28b exhibited high sensitivity and specificity to a CL serum pool. More importantly, NGP28b reacted strongly and specifically with individual sera from distinct clinical forms of TL, especially with SC sera, with 94% sensitivity and 97% specificity, by post-two-graph receiver-operating characteristic curve analysis. Contrary to NGP29b, NGP28b showed low cross-reactivity with Chagas disease and control (NEC/EC) sera. Additionally, seroreactivity of CL patients against NGP28b was significantly decreased after successful chemotherapy, indicating that L. braziliensis-specific anti-α-Gal antibodies may serve as an early biomarker of cure in CL. Our data also points towards the applicability of L. major type-2 GIPL-3-derived Galα1,6Galα1,3Galfß glycotope for the serological diagnosis of American TL, particularly of the subclinical form.
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Leishmania braziliensis , Leishmaniose Cutânea , Biomarcadores , Glicoproteínas , Humanos , Testes SorológicosRESUMO
Patients with cutaneous leishmaniasis (CL) due to Leishmania braziliensis infection have an exacerbated inflammatory response associated with tissue damage and ulcer development. An increase in the rate of patients who fail therapy with pentavalent antimony has been documented. An adjuvant therapy with an anti-inflammatory drug with the potential of Leishmania killing would benefit CL patients. The aim of the present study was to investigate the contribution of peroxisome proliferator-activated receptor-γ (PPAR-γ) activation by pioglitazone in the regulation of the inflammatory response and L. braziliensis killing by monocytes. Pioglitazone is an oral drug used in the treatment of diabetes, and its main mechanism of action is through the activation of PPAR-γ, which is expressed in many cell types of the immune response. We found that activation of PPAR-γ by pioglitazone decreases the inflammatory response in CL patients without affecting L. braziliensis killing by monocytes. Our data suggest that pioglitazone may serve as an adjunctive treatment for CL caused by L. braziliensis.
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Leishmania braziliensis , Leishmaniose Cutânea , Humanos , Leishmaniose Cutânea/tratamento farmacológico , Monócitos , PPAR gama/uso terapêutico , Pioglitazona/farmacologia , Pioglitazona/uso terapêuticoRESUMO
BACKGROUND: Leishmaniases are neglected tropical diseases that inflict great burden to poor areas of the globe. Intense research has aimed to identify parasite genetic signatures predictive of infection outcomes. Consistency of diagnostic tools based on these markers would greatly benefit from accurate understanding of Leishmania spp. population genetics. We explored two chromosomal loci to characterize a population of L. braziliensis causing human disease in Northeast Brazil. METHODOLOGY/PRINCIPAL FINDINGS: Two temporally distinct samples of L. braziliensis were obtained from patients attending the leishmaniasis clinic at the village of Corte de Pedra: (2008-2011) primary sample, N = 120; (1999-2001) validation sample, N = 35. Parasites were genotyped by Sanger's sequencing of two 600 base pairs loci starting at nucleotide positions 3,074 and 425,451 of chromosomes 24 and 28, respectively. Genotypes based on haplotypes of biallelic positions in each locus were tested for several population genetic parameters as well as for geographic clustering within the region. Ample geographic overlap of genotypes at the two loci was observed as indicated by non-significant Cusick and Edward's comparisons. No linkage disequilibrium was detected among combinations of haplotypes for both parasite samples. Homozygous and heterozygous genotypes displayed Hardy-Weinberg equilibrium (HWE) at both loci in the two samples when straight observed and expected counts were compared by Chi-square (p>0.5). However, Bayesian statistics using one million Monte-Carlo randomizations disclosed a less robust HWE for chromosome 24 genotypes, particularly in the primary sample (p = 0.04). Fixation indices (Fst) were consistently lower than 0.05 among individuals of the two samples at both tested loci, and no intra-populational structuralization could be detected using STRUCTURE software. CONCLUSIONS/SIGNIFICANCE: These findings suggest that L. braziliensis can maintain stable populations in foci of human leishmaniasis and are capable of robust genetic recombination possibly due to events of sexual reproduction during the parasite's lifecycle.